Steering mechanism



Dec. 4, 1945. c. c. UTZ 2,390,231 l STEERING MECHANI SM INVENTOR ATTORNEYS.

Dec. 4, 1945. C, C DTZ 2,390,231

STEERING MECHANI SM INVEN TOR ATTORNEYS.

Dec. 4, 1945. c. c. U12 2,390,231

STEERING MECHANISM Filed NOV. l0, 1945 3 Sheets-Sheet 5 E@ El IN VEN TOR Patented Dec. 4, 1945 UNITED S'IA'I'IEQSl PATENT OFFICE STEERING MECHANISM Chester C Utz, Magnolia (Redford Station)L Mich., assigner to Chrysler Corporation, Highland Parle Mich., a` corporation of Delaware Appl-matten Ncycmber 10, 1943, Serial No.' 503,701

1,2 Claims.

This invention relates to` steering mechanism for motor vehicles, and it has particular reference to an improved steeringA linkage readily adapted to automobiles wherein the steering column is remotely positioned with respect to the vertical longitudinal mid plane ofthe car.

Heretoiore, it has been commonplace to locate the steering Wheel to one side of. the' vertical longitudinal mid plane and to connect the wheel to the front or steerable wheels of thevehicle by any of a variety of linkages. However, when the links extending to each wheel are of different lengths, a limit is reached for the position of the column with respect to the vertical longitudinal mid plane which, if exceeded, creates poor steering geometry, wheel fight, and unsatisfactory distribution of stresses among the various components of the. mechanism. The present invention provides a solution for these defects.

An object of the present invention is to provide an improvement in steering mechanism for vehicle wheels.

Another object is to improve steering mechanism for Vehicle wheels, which mechanism is operable from a point well displaced from the vertical longitudinal mid plane of the vehicle.

A further object is the provision of an improvement in a steering mechanism in which long and short tie rods are used because of control of the steering mechanism from a point displaced from the vertical longitudinal mid plane ofthe vehicle.

Another object is to provide ay control for steering mechanism operable farther to the side of the vehicle than the operable limit of difference inr length of the rods will permit.

Other objects will appear from the disclosure.

Fig. l is a plan v-ieW of the iront end of an automobile chassis incorporating the invention;

Fig. 2 is an enlarged` fragmentary plan view of the steering linkage shown in Figfl;

Figs. 3, 4, 5 and 6i are sectional views taken substantially along theorrespondingly numbered section lines of Fig. 2;

Fig. 7 is a fragmentary side elevation showing the linkage mounted on the chassis frame; and

Figs, 8', 9 and 10 are simplified plan views of variants of the novel linkage.

The invention is shown in Fig. l as applied to an automobile having longitudinal frame members 2| and 22 coupled at the front end by a cross member 23, to which are aflixed to a pair of steerable road .wheels 24 and 25. These Wheels are independently mounted. by means including upper and lower pivotect and angular-ly disposed arms 2 6 and 2-1, Whose pivotv axes 26av and 21a converge and intersect at approximately the vertif. cal longitudinal mid plane of the car. Other details of the Wheel mounting need not be dwelt upon here, since they are. Well understood and form no part of thisY invention. Steering arms 28A and 28 are connected to each Wheel assembly, to provide link members for turning and Vsteer-- ing purposes. The arm 2,8; is connected, through a pivot 3l, to another link 33, which may be termed a short tie rodj, and the arm '23; is connected, through a pivot 32, to a 3 4 which constitutes a long tie rod. These tie rods are connected to, and are actuated by, mechanism generally designated by the reference numeral 35 in Fig. l, and hereinafter more fully described. Such mechanism includes a steering chuck;4 36 the details of which are well k-noWn,- and a shaft 31 which extends up Within the carbQdyfor rotation by the driver through the usual steerf. ing wheel.

From the standpoint of theoretical geometry the tie rods to the steerable wheels should be. of equal length, but actually tie rodsofellla-l length, when of a length to extend to a commun point at the Vertical longitudinal mid plane of the car, set up wheel fight. One known manner of eliminating wheel fight is to use one short tie rod and to increase the length of the other tie rod to make it reach the short tie rod. This is the arrangement of the tiev rods 33 and 3.4, Ther-e' is a practical limit to the shortness of the short tie rod, or, in other Words, the short tie rodA has some significant length with respect to the distance between the wheels and the length of. the other tic rod. Inl the construction o i Fig. l the ratio ot the lengths should not exceed. ten to three.

In order to stay within this limit, it is therefore necessary to position the steering column and chuck 36 at a suitable place in the car, andr generally Vin line with the meeting ends of the links 33 and 34. For many automobiles, this is entirely feasible, butv the desired alignment is not attainable in cars equipped with comparatively wide front seats,-i. e., those which will safely and comfortably hold three normal size adults instead of the usual two. With such cars, the necessity of providing adequately Wide seats impels the shifting, to the left in American automobiles, of the steering wheel and column to such a degree that the desired alignment and rod ratio cannot be maintained.

According to the present invention', both the desiredV rod length ratio and increase infront seat Width can be obtained, by means of a novel linkage mechanism. Referring to Figs. 2 and 1, the steering chuck 36 is mounted on the left hand frame member 2|, being secured thereto at an angle to the vertical by a clamp 38 and bolts 39. Rotation of the steering shaft rod 31 actuates the worm, or other mechanism, to swing a pitman arm 4|, which is carried by a rotatable shaft 42, contained in a housing portion 43 of the chuck 36, being secured by a lock nut 44 (see Fig. 4). The pitman arm 4I extends forwardly and downwardly, and it is formed at its front end with an eye 45 adapted to receive a stud 46 formed on a U-shaped link 41. Rubber bushings 48 are inserted in the eye and around the stud, being held in place by an upper washer 49 abutting a shoulder formed on link 41, and a second washer 52 engaged by a lock nut 53. The bushings 48 fit snugly between the stud 46 and the wall of the eye, so that, when the nut 53 is drawn up, free rotation of the stud and link 41, with respect to the arm 4|, cannot occur. However, limited relative movement may occur when the angle between the arm 4| and the link 41 is changed, the bushings yielding to the torsional stresses applied thereto. The resilience of the bushings also serves to cushion the mechanism from transmission of road shocks and vibrations back to the steering wheel, while the torsional strain developed aid in restoring the linkage to a straight line driving position.

The opposite end of the link 41 is formed with a stud 54, which, by the same means as have just been described, is secured in an eye portion 56 of an auxiliary arm 51, extending generally parallel to the arm 4|. The rear portion of the arm 51 is provided with an upstanding stud 58, rotatably mounted -in a bearing boss 59 formed at the end of a bracket 6| which is'integral with the housing section 43. The arms 4| and 51 are therefore both free to rotate, but are constrained to move in unison andV parallel to each other, by the interconnection provided by the link 41, As such rotary movement takes place, the change in angularity is absorbed by the torsional strains set up in the bushings 48. Y

The frontend of the arm 51 is formed in tw branches 63 and 64, extending to the left and right respectively, and so turned, as shown in Figs. 5 and 6, that the left branch 63 terminates in a plane below the axisr of the arm 51, while the right hand tine 64 lies above. This produces a configuration something like a Wishbone, and compensates for the difference in angularities which otherwise would exist between the short and long tie rods 33 and 34, which are connected to the branches. The branch 63 terminates in an eye 65, formed with a tapered bore receiving a stud 66, which is secured by a lock nut 61. The upper end of the stud is of spherical shape, to engage a semi-spherical washer 68 contained in socket piece 69 having a threaded rod'1 I extending therefrom. The rod is threaded into an internal tap in the short tie rod 33, as indicated in Fig. 1. The ball joint between the stud 66 and piece 69 is maintained by a spring and washer assembly 12, held within the socket and against the end of the stud by a cap 13. The rod 1|,and its attached tie rod 33, may therefore turn in any direction with respect to the arm 51, either during steering operations, or.in response to vertical movements of the wheel 24.

The long tie rod 34 is connected in like manner to the branch 64, except that it lies above the axis of the arm 51, instead of being below it. The connection is made through an eye on the branch 69, ball connected to a stud 16 with spherical head, and threaded rod 11, by duplicates of the parts heretofore described. Each of the joints is protected against dirt by rubber sleeves 18 which encircle the studs, and are secured to the socket pieces by bands 19.

When the steering post 31 is turned, the arm 4| is swung to the right or left, as the case may be, thus imparting a like motion to the arm 51, and thereby the rods 33 and 34. The axes of the studs 66 and 16 are so located, with respect to the axis of the stud 58, that the pivoted end of the link 1| travels in a substantially linear direction when the motion is in one direction, and the link 11 follows a flat path when the motion is in the opposite direction. The length of the bracket 6| is, of course, so chosen as to impart a working length to the short tie rod 33 which satisfies the ratio heretofore discussed.

The link system, 4|, 41, 511 6|, need not be rectilinear, as shown in Fig. 2, but may be Varied to suit special conditions that may be encountered. As shown in Fig. 8, a bracket Sla is turned back toward the mid-portion of the car, and its length is increased to maintain the same transverse distance between the axis of shaft 42 and stud 58 as in Fig. 2. The effective length of Van arm 51a is thereby increased; i. e., the length of the arm 51a between link 41 and stud 58 is greater than the length of the pitman arm 4| between link 41 and shaft 42. Thus an even iiatter arc is imparted to the pivoted ends of rods 1| and 11. This curtails the vertical displacements to which these ends are subject during operation.

Fig. 9 shows a similar link system, but here the right end of a link 41b is somewhat forward oi its left end. Thus the length of an arm 51h between link 41b and stud 58 is greater than the length of pitman arm 4| between link 41D and shaft 42. 'As in Fig. 8, a flatter arc is impaited to the ends of rods 1| and 11.

In Fig. l0, on the other hand, a link 41c has its right end rearward to its left end, the result being that the length of an arm 51c between link 41o and stud 58 is less than the length of pitman arm 4| between 41o and shaft 42. Thus the rate of angular movement of arm 51C is greater than that of pitman arm 4|, and a more rapid action or response of the road wheels to movement of the steering wheel is obtained.

It will be apparent from the foregoing description that new and novel steering mechanisms have been provided. Essentially they involve linkages permitting a displacement of a steering member from the region to which the inner ends of the tie rods extend. The drawings illustrate the various forms of the novel mechanisms as applied to tie rods of unequal lengths, and these novel mechanisms are of special advantage when they are applied to these arrangements of the rods, for then the dimensions of the linkage transverse of the car may be small, and the linkages function with greater facility. However it is to be understood that the invention is not to be limited to these arrangements of tie rods.

While the invention hals been described with respect to one form and variations and modifications thereof, it is intended that it should not be limited thereto, but should be accorded a scope commensurate with the context of the following claims.

I claim:

1; In a steering mechanism for a car having steerable road wheels, a. steering chuck mounted to one side of the vertical longitudinal mid plane aegon-ai:

of .the car andadjacent: one ofv the` road; wheels,

a pitman arm rotatably connected" to and Oper-.- atedf by the chuck, ay bracket extending inwardly toward the verticaly longitudinali mid' plane ofr the car from the chuck, a second: arr-n rotatably mounted in the bracket, a link interconnecting the free endl of thepitman arm and the second arm intermediate the bracket andthe forward end of thel second arm, ball joints on theforward end of thel second arm, and relatively short and long tie rods connected to thel ball joints and respectivelyv toI the road wheels.

2; Steering mechanism for a vehicle having steerable wheels, comprisinga rst operator-controlled arm having a pivotal mounting at one end on the vehicle and extending in a certain general direction from the pivotal mounting, a second arrnv displaced from the first arm and having a pivotalm-ounting at one endon the vehicle and extending from its pivotal mounting in the same general direction as the rst arm, and link means interconnecting a point on the first arm spaced from its pivotal mounting and a point on the second arm h-aving a greater spacing from its pivotal mounting than that of the point on the first arm from its pivotal mounting, and tie rods connecting the free end of the second arm and the wheels.

3. Steering mechanism for a vehicle having steerable wheels, comprising a first operatorcontrolled arm having a p ivotal mounting at one end on the vehicle and extending in a certain general direction from the pivotal mounting, a second arm displaced from the rst arm and having a pivotal mounting at one end on the vehicle and extending from its pivotal mounting in the same general direction as the iirst arm, link means interconnecting a point on the rst arm spaced from its pivotal mounting and a point on the second arm having a lesser spacing from its i pivotal mounting than that of the point on the first arm from its pivotal mounting, and tie rods connecting the free end of the second arm and the wheels.

4. Steering mechanism for a vehicle having steerable wheels, comprising a first operator-controlled arm having a pivotal mounting at one end on the vehicle and extending generally longitudinally of the vehicle forwardly from its pivotal mounting, a second arm displaced from the rst arm transversely of the vehicle and having a pivotal mounting at one end on the vehicle rearward of that of the rst arm and extending generally longitudinally of the vehicle forwardly from its pivotal mounting, link means interconnecting a point on the rst arm spaced from its pivotal mounting and a point on the second arm having a greater spacing from its pivotal mounting than that of the point on the first arm from its pivotal mounting, and tie rods connecting the free end of the second arm and the Wheels.

5. Steering mechanism for a vehicle having steerable wheels, comprising a iirst operator-controlled arm having a pivotal mounting at one end on the vehicle and extending generally longitudinally of the vehicle forwardly from its pivotal mounting, a second arm displaced from the rst arm transversely of the vehicle and having a pivotal mounting at one end on the vehicle directly transverse of that of the first arm and extending generally longitudinally of the vehicle forwardly from its pivotal mounting, link means interconnecting a point on the first arm spaced from its pivotal mounting and a point on the second arm forward of the point on the first arm CII having a greater spacing from. itsl pivotal moimtp, ing: than that of the` point. on the rst. arm from its: pivotal mounting., and tie rodsi connecting the. free end of the` second. arm and the wheels.

6.. Steering mechanism. for-a vehicle having steerable Wheels, comprising a, first. operatorecone trolled arm having a pivotal mounting at one end on the vehicle and; extending generally longitudinally of the vehicle. forwardly from its piv-l otal mounting, a second arm displaced fromthe iirst arm transversely of the vehicle and having a pivotal mounting atone end.v on the vehiclef di;. rectly transverse off that of the iirst arm and ex, tending generally longitudin-ally of the vehicle forwardly from i-ts-A pivotal mounting, link means interconnectingV apoint on the. first arm spaced `from its pivotal mounting andra point on the secg ond arm rearward of the point on the firstarm having al lesserspacing from its pivotal mount.. ing than that of the.- point on the firstv arm from its pivotal: mounting, and tie rods connecting the free endlv of the second` arm andthe wheels,

7. Steering mechanism for a vehicle having steerable Wheels, comprising a rst operatorcontrolled arm having a pivotal mounting at one end on the vehicle and extending in a certain general direction from its pivotal mounting, a second arm displaced from the first arm and having a pivotal mounting at one end on the vehicle and. extending in the same general direction as the` first arm, link means interconnecting a point on the first arm spaced from its pivotal mounting and a point on the second arm having a spacing from its pivotal mounting diierent from that of the point on the flrst arm from its pivotal mounting, and tie rods connecting the free end oi the second arm and the Wheels.

8. Steering mechanism for a vehicle having a frame and steerable wheels, said mechanism comprising a steering chuck mounted on one side of the car frame, a pitman arm rotatable through said chuck, a bracket extending from the chuck inwardly toward the vertical longitudinal mid plane of the car, a second arm pivotally connected to the bracket, a link interconnecting a point on the pitman arm spaced from its axis of rotation and a point on the second arm having a greater spacing from its pivotal mounting than that of the point on the pitman arm from its axis of rotation to form a quadrilateral linkage wherein a certain angular movement of the pitman arm produces a certain less angular movement of the second arm, relatively short and long tie rods pivotally connected to the second arm, and means for connecting said rods to the steerable wheels of the car.

9. In a steering mechanism for a car having steerable road wheels, a steering chuck mounted to one side of the vertical longitudinal mid plane of the car and adjacent one of the road wheels, a pitman arm rotatably connected to and operated by the chck, a bracket extending inwardly toward the vertical longitudinal mid plane of the car from the chuck, a second arm rotatably mounted in the bracket, a link interconnecting a point of the pitman arm spaced from its axis of rotation and a point on the second arm having a lesser spacing from its axis of rotation than that of the point on the pitman arm from its axis of rotation, and relatively short and long tie rods connected to the second arm and respectively to the road wheels.

10. vSteering mechanism for a vehicle having steerable wheels, comprising a rst operator-controlled arm displaced to one side of the vertical longitudinal mid plane of the vehicle, having a pivotal mounting at one end on the vehicle, and extending in a certain general direction from the pivotal mounting, a second arm displaced from the first arm on the side thereof toward the vertical longitudinal mid plane and having a pivotal mounting at one end on the vehicle and extending from its pivotal mounting in the same general direction as the rst arm, link means interconnecting the arms `for causing movement of the rst arm to effect generally parallel movement'of the second arm, and tie rods leading to the steerable wheels and directly connected to the second arm at a portion thereof spaced farther from the pivotal mounting thereof than is the region of connection of the link means interconnecting the arms.

11. Steering mechanism for the road Wheels of a. motor car comprising a chuck including a rotatable pitman arm mounted to one side of the vertical longitudinal mid plane of the car, a second arm rotatably mounted between the pitman arm and the vertical 1ongitudina1 mid planeof.

the car, a link interconnecting the arms for conjoint movement, and relatively short and long tie rods directly connected to the second arm at a region thereof spaced farther from the pivot of the second arm than is the region of connection of the link interconnecting the arms and leading to the road wheels.A

12. Steering mechanism for the road wheels of a motor car comprising a chuck including a rotatable pivotally mounted pitman arm, a second pivotally mounted arm extending generally parallel to the pitman arm in the same direction from its pivot mounting as the Pitman arm, link means interconnecting the arms for eiecting conjoint movement thereof, and tie rods leading to the road wheels and directly connected to the second arm at a region thereof farther from the pivot mounting than is the region of connection of the link means.

' CHESTER C. UTZ. 

